Device for dispensing a divided solid material inside a receptacle

ABSTRACT

This device comprises an element driven in rotation about a vertical axis, placed at an outlet of a passage used for introducing a divided solid material into a receptacle. The element comprises two conduits for dispersing the material, each having a curved shape and an opening through which the material can flow out into the receptacle. The conduits are curved about an axis perpendicular to an axis of rotation of the element but in opposite directions from one another. Each of the conduits further comprises at least one longitudinal partition extending over a length of the conduit.

FIELD OF THE INVENTION

The present invention relates to a device for dispersing a divided solidmaterial, particularly in the form of granules or rods, inside areceptacle such as a tank.

DESCRIPTION OF THE RELATED ART

The invention finds a particularly advantageous application in thepetrochemical industry, for filling reactors with catalyst material, butcould be used for filling any type of receptacle with any type ofdivided solid material provided that the bed of material deposited inthis receptacle has to be flat, uniform and/or dense, and provided thatfilling has to be performed with a limited emission of dust. Theinvention could thus, for example, be used for filling grain silos.

In the field of the petrochemical industry, it is commonplace for fluidsto be treated by passing these fluids through a bed of catalystmaterial. This catalyst material is in the form of rods a fewmillimeters long placed inside the tank of the reactor which isgenerally of cylindrical shape.

One method of charging such a reactor consists in purely and simplytipping the catalyst material into the tank. This material does,however, have the disadvantage of depositing itself in the form of amore or less conical heap, the compaction of which is far greater in thecentral part than in the peripheral parts. The result of this is thatthe fluid to be treated tends to prefer to pass through the thinner andless dense layers, which appreciably reduces the efficiency of thereactor.

In addition, the catalyst material is frequently based on alumina, andis therefore friable and prone to breaking up. The rods of which it ismade break up to some extent as they are being tipped out, which lessensthe efficiency of the treatment and leads to a significant loss ofmaterial through the emission of dust.

Furthermore, the amount of material that can be placed in the reactor isreduced.

Another filling technique consists in providing, at the outlet of theconduit used for introducing the material into the tank, a dispersinghead comprising plates or blades driven in rotation, which break up thestream of material.

This kind of head improves the distribution of product in the tank,without, however, making it possible to obtain a perfectly uniform bedof material. What happens is that dispersion adopts highly random paths,and the rods often reach the peripheral wall of the tank before reachingthe bottom of this tank, and therefore tend to accumulate as a matter ofpreference at the base of this wall. The result of this is that theupper face of the bed obtained is more or less in the shape of a conicaldish, also creating passages that the fluid that is to be treatedprefers to take.

Furthermore, the rods strike the plates or blades, and this causesdamage to them and the emission of abundant quantities of dust.

Certain problems in regulating the rate of flow of the material arise,and the density of the bed obtained is not very high.

SUMMARY OF THE INVENTION

The present invention sets out to overcome all these drawbacks byproviding a dispersing device that makes it possible to deposit thematerial in the form of a flat, uniform bed of high density without therisk of damaging the granules or rods that make up this material, andwith limited emissions of dust.

The device to which it relates comprises, in a way known per se, anelement driven in rotation about a vertical axis, placed at the outletof the duct for introducing divided solid material into the receptacle.

According to the invention, this element comprises two conduits fordispersing the material, each having a curved shape and an openingthrough which the material can flow out into the receptacle; theseconduits are curved about one and the same axis perpendicular to theaxis of rotation of said dispersing element but in opposite directionsfrom each other, and are shaped in such a way that their outflowopenings are each positioned on one side of the axis of rotation of saiddispersing element, more or less in one and the same diametral plane,and are directed in opposite directions; each of these conduitsfurthermore comprises at least one longitudinal partition extending overall or over a large part of its length, this partition being capable ofsplitting the stream of material and of distributing the flow thereof,against centrifugal force, over all or over a large part of the outflowopening.

As a result their aforementioned curved shape, these conduits eliminateany impact of the material as it flows and, when the element is drivenin rotation, allow the material to be sprayed out in two helical streamsin opposite directions, the width of which more or less corresponds tothe radius of the receptacle that is to be filled. The speed of rotationof the dispersing element may be regulated, as a function of the type ofmaterial, of the outflow speed thereof and of the distance separatingthis element and the bottom of the receptacle or the surface of thematerial, so that the granules or rods situated on the outside of thesestreams drop more or less to the base of the side wall of thereceptacle.

A more or less flat bed of material with uniform compaction is thusobtained, without damage to the granules or rods or emission of dust.

The cross section of the conduits may be relatively small so that thetwo helical streams spread a relatively limited amount of this materialon each revolution of said element, and the speed of rotation of saidelement may, by contrast, be relatively high. A bed of very high densityis thus obtained without this in any way affecting the speed with whichthe receptacle is filled, given said speed of rotation.

As a preference, the distance between axes of two adjacent partitionsincreases from that part of each opening that lies on the same side asthe axis of rotation of the dispersing element toward that part of thesame opening that lies on the opposite side. This positioning of thepartitions allows better distribution of the material within the streamemitted by the conduit.

According to a preferred embodiment of the invention, each conduit has ashape more or less in the form of half a helicoid turn. This particularshape has in the past yielded excellent results.

Advantageously, the dispersing element comprises additional meansallowing the flow of the material to be regulated, such asposition-adjustable plates, situated at the level of the conduits so asto increase or decrease the cross section of these conduits, or situatedfacing the openings of these conduits. The plates situated facing theopenings of the conduits may have inclined edges capable of suitablydeflecting the stream of material slightly in the vertical plane, ifnecessary.

As a preference, the device according to the invention comprises asystem for sucking up the dust of the divided solid material, actinginside the receptacle that is to be filled and/or inside the deviceitself.

BRIEF DESCRIPTION OF THE DRAWINGS

For a good understanding thereof, the invention is described once againhereinbelow with reference to the appended schematic drawing which, byway of non-limiting example, depicts one preferred embodiment of thedispersion device to which it relates.

FIG. 1 is a simplified part view in longitudinal section of a reactorwhich can be used in the field of the petrochemical industry;

FIG. 2 is a view in longitudinal section of the device according to theinvention;

FIG. 3 is a perspective view of the dispersing element that this devicecomprises; and

FIG. 4 is a view of this element in section on the line IV—IV of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 depicts a reactor used in the field of the petrochemical industryto treat fluids, this treatment being performed by passing these fluidsthrough a bed of catalyst material contained in the cylindrical tank 1of this reactor.

This catalyst material is in the form of rods a few millimeters long andis conveyed into the tank 1 by a conduit 2.

A dispersing device 3 is placed at the outlet of the conduit 2, todistribute the catalyst material in a flat, uniform and dense bed.

As can be seen in FIGS. 1 and 2, this device 3 comprises a stationarytubular part 5, a tubular part 6 which is mounted so that it can rotatewith respect to the part 5, and a dispersing element 7 mounted on thelower end of the part 6.

The part 5 is fixed to a supporting structure (not shown) by means offour U-shaped bars 10 bolted onto blocks 11 and is connected to theconduit 2. Internally, it comprises two series of four radialcrossmembers 12 situated 900 apart. These crossmembers 12 are fixed tothe wall of the part 5 by one of their ends and are connected by theirother ends to an axial support structure 14 supporting a motor 15 thatdrives the rotation of the part 6.

The part 5 also comprises two series of holes 20 formedcircumferentially through its wall. An annular box structure 21 is fixedto this part 5 facing these holes 20, this box structure 21 beingconnected to a source of vacuum by means of a hose (not shown) fittedover an end piece 22.

A second annular box structure 23 is fixed to the part 5 underneath thebox structure 21. This box structure 23 has a lower annular opening 24and is connected to a source of vacuum by means of a hose (not shown)fitted over an end piece 25.

Internally, the part 6 comprises two series of four radial crossmembers27 situated 90° apart. These crossmembers 27 are fixed to the wall ofthe part 6 by one of their ends and are connected, by their ends, to anaxial shaft 28 fixed to the shaft of the motor 15.

The diameter of the part 6 is greater than that of the part 5, and theassembly is shaped in such a way that the upper end of the part 6 coversthe lower end of the part 5 when the shaft 28 is fixed to the shaft ofthe motor 15.

The lower end of the part 6 and the upper end of the element 7 each havea flange 29, 30 allowing this element 7 to be mounted on this part 6using bolts 31.

The element 7 is hollow and comprises a primary conduit 35 which, in itslower part, splits into two secondary conduits 36.

FIG. 3 more particularly shows that the primary conduit 35 changes froman opening of circular shape in its upper part to an opening ofrectangular shape and of small cross section in its lower part, so thatit has two opposed walls 35a which gradually flatten out toward thislower part.

Each of the secondary conduits 36 has a curved shape, more or less inthe form of half a helicoid turn, and ends in an opening 37 throughwhich material flows out into the tank 1. The half turns are woundaround one and the same horizontal axis and follow on from one anotherin space, so that the openings 37 are each situated on one side of theaxis of rotation of the element 7, in one and the same diametral plane,and are oriented in opposite directions.

FIGS. 3 and 4 show that each of the conduits 36 internally comprisesseven longitudinal partitions 40 which extend over all of its length.The distance between axes of two adjacent partitions 40 increases fromthat part of each opening 37 that lies on the same side as the axis ofrotation of the dispersing element 7 toward that part of the sameopening 37 that lies on the opposite side. In the example depicted, fora total width of each conduit 36 of 300 mm, and a height of the order of20 mm, the distance between the side wall of the conduit 36 and theadjacent partition 40 situated closest to the axis of rotation of theelement 7 is 30 mm, then, moving away from this axis of rotation, thedistances between two adjacent partitions 40 are, respectively, 30 mm,35 mm, 35 mm, 40 mm, 40 mm, and 45 mm, and the distance between the sidewall of the conduit 36 and the adjacent partition 40 situated furthesttoward the outside is 45 mm.

Furthermore, the two walls 35 a have plates 50, the position of whichcan be adjusted in the direction perpendicular to the longitudinal edgesof the lower opening of the conduit 35, these plates 50 making itpossible to increase or to decrease the cross section for the passage ofthe catalyst material along the conduits 36. The position of theseplates 50 is adjusted by means of slots formed in the walls 35 a, ofthreaded rods secured to the plates 50 passing through these slots, andof nuts screwed onto these threaded rods to make it possible, dependingon whether they are tightened or loosened, to prevent or to allowmovement of the plates. The plates 50 cover said slots regardless oftheir position, which means that no product can flow out through theseslots.

The conduits 36 themselves comprise vertical walls 51 placed more orless in the plane of their openings 37, along which position-adjustableplates 52 can be moved in a direction parallel to the plane of theseopenings 37. Position adjustment of the plates 52 is achieved in thesame way as described above, using slots formed in the walls 51,threaded rods secured to these plates 52 passing through these slots,and nuts screwed onto these threaded rods to make it possible, dependingon whether they are tightened or loosened, to prevent or to allowmovement of the plates 52. The latter have inclined edges 52 a capableof deflecting the stream of catalyst material slightly in the verticalplane, if necessary, depending on the type of material.

In practice, driving the element 7 in rotation makes it possible, byvirtue of the conduits 36, for the catalyst material to be sprayed outin two helical streams in opposite directions, the width of which moreor less corresponds to the radius of the tank 2.

For an element 7 situated about four meters from the bottom of the tank2 and a tank with a diameter of about three meters, the speed ofrotation of the element 7 will be about 90 revolutions per minute. Thisspeed needs to increase by 10 to 12% when the level of the catalystmaterial rises by one meter.

The partitions 40 allow the stream of material to be split up and allowits flow to be distributed, against centrifugal force, over a large partor over all of the openings 37.

The conduits 36 also eliminate any impact of the material as it flows.

The plates 50, 52 make it possible to increase or to decrease the crosssection of these conduits 36 so as to regulate the flow of the catalystmaterial, if need be.

The box structures 21, 23 themselves allow the dust from the catalystmaterial to be collected, both inside the tank 2 and inside the part 5.

What is claimed is:
 1. Device for dispersing a divided solid materialinside a receptacle, comprising an element driven in rotation about avertical axis, placed at an outlet of a passage used for introducing thedivided solid material into the receptacle, wherein the elementcomprises two conduits for dispersing the material, each having a curvedshape and an opening through which the material can flow out into thereceptacle; the conduits are curved about an axis perpendicular to anaxis of rotation of said element but in opposite directions from eachother, and are shaped in such a way that the openings are eachpositioned on one side of the axis of rotation of said element, in adiametral plane, and are directed in opposite directions; each of theconduits further comprises at least one longitudinal partition extendingover a length of the conduit, the partition being capable of splitting astream of material and of distributing a flow thereof, againstcentrifugal force, over the outflow opening.
 2. Device according toclaim 1, further comprising means for regulating a speed of rotation ofthe dispersing element.
 3. Device according to claim 2, wherein theregulating means regulates the speed of rotation of the element as afunction of at least one of factors including a type of material, anoutflow speed thereof, a distance between the element and a bottom ofthe receptacle, and a distance between the element and a surface of thematerial.
 4. Device according to claim 1, wherein a cross section of theconduits is relatively small so that two helical streams of materialflowing out from the openings spread a limited amount of the material oneach revolution of said element, and a speed of rotation of said elementis, by contrast, relatively high.
 5. Device according to claim 4,wherein a total width of each conduit is 300 mm and a height thereof isof an order of 20 mm.
 6. Device according to claim 1, wherein a distancebetween axes of two adjacent partitions increases from that part of eachopening that lies on a same side as the axis of rotation of the elementtoward that part of the same opening that lies on an opposite side. 7.Device according to claim 6, wherein, for a total width of each conduitof 300 mm, and a height of an order of 20 mm, a distance between a sidewall of the conduit and an adjacent partition situated closest to theaxis of rotation of the element is 30 mm, and, moving away from the axisof rotation, distances between two adjacent partitions are,respectively, 30 mm, 35 mm, 35 mm, 40 mm, 40 mm, and 45 mm, and thedistance between the side wall of the conduit and the adjacent partitionsituated further toward an outside is 45 mm.
 8. Device according toclaim 1, wherein each conduit has a shape of half a helicoids turn. 9.Device according to claim 1, wherein the element comprises adjustablemeans for regulating the flow of the material.
 10. Device according toclaim 9, wherein said adjustable means comprises plates which aresituated facing the openings of the conduits and have inclined edgescapable of slightly deflecting the stream of material in a verticalplane.
 11. Device according to claim 9, wherein the adjustable means isplaced at a level of the conduits so as to increase or decrease thecross section of the conduits.
 12. Device according to claim 9, whereinthe adjustable means is placed facing the openings of the conduits. 13.Device according to claim 1, further comprising a system for sucking updust of the divided solid material.
 14. Device according to claim 13,wherein the system acts inside the receptacle that is to be filled andinside the device itself.
 15. Device according to claim 13, wherein thesystem acts inside the receptacle that is to be filled or inside thedevice itself.
 16. Device according to claim 1, wherein the dividedsolid material is in the form of granules or rods.
 17. Device accordingto claim 1, wherein the receptacle is a tank.
 18. Device according toclaim 1, wherein the at least one longitudinal portion extends over allor a majority portion of the length of the conduit.
 19. Device accordingto claim 1, wherein said partition is capable of distributing the flowthereof over all or a majority portion of the outflow opening.